Heard in television ads for cancer treatment centers, the phrase investigational drugs. From an FDA site on “Access to Investigational Drugs”:

Investigational or experimental drugs are new drugs that have not yet been approved by the FDA or approved drugs that have not yet been approved for a new use, and are in the process of being tested for safety and effectiveness.

This passage treats investigational and experimental as synonyms in the drug context — but then the site goes on to use investigational exclusively. This specialized use of investigational (as opposed to the transparent general use ‘of or relating to investigations’) seems to be fairly recent — recent enough that it’s not in the dictionaries I’ve consulted. It seems to have replaced experimental as the appropriate technical term for drugs undergoing testing, perhaps because some people in the relevant community had come to feel that experimental no longer sounded sufficiently technical, but had become part of ordinary language.

A bit more from the FDA site, showing the exclusive use of investigational:

Patients may decide to seek access to investigational drugs for different reasons. Some patients with serious or life-threatening illnesses seek treatment with investigational drugs if FDA-approved therapies are not working or if their side effects are too severe. Others may have heard about promising early study results for a specific investigational drug, and they might want to learn more.

Investigational drugs are available through two pathways designed to protect patients, because an investigational drug may pose unknown risks to patients and we do not know if it is effective. Patients may be eligible to receive an investigational drug as a participant in a clinical trial or as part of an expanded access program  (also known as compassionate use).

Compare experimental in NOAD2, which lists three current senses:

(of a new invention or product) based on untested ideas or techniques and not yet established or finalized: an experimental drug.

• (of a work of art or an artistic technique) involving a radically new and innovative style: experimental music.

• of or relating to scientific experiments: experimental results.

We can see a specialization here, from ‘of or relating to experiments”, specifically scientific experiments, to the testing of ideas or techniques, and something similar has now happened to investigational.



3 Responses to “investigational”

  1. Bob Richmond Says:

    Well, I got out of medical school 50 years ago, and the term “investigational drug” has been in common use in medicine for as long as I can remember.

    Whenever I hear of “experimental” music I always want to be one of the controls in the study.

  2. arnold zwicky Says:

    Bonnie Taylor-Blake on ADS-L:

    Arnold’s piece on “investigational” and “investigational drugs” reminds me of a hot phrase in the fields of pharmacology and medicinal chemistry.

    “Druggable targets” are proteins or peptides and the like (in the body) to which pharmacologists/medicinal-chemists strive to design agents (drugs) that will affect the function and/or structure of the said proteins or peptides (so as to improve human health).

    This brings us to “druggability.” See here.

    “Druggability” and “druggable” don’t seem to be showing up in standard dictionaries such as OED and Merriam-Webster.

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